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Mechanical probes of various sizes and shapes were used to determine thresholds for the perception of pressure, sharpness, and pain on the human finger. As force increased, perception changed from dull pressure to sharp pressure to sharp pain. With the smallest probe (0.01 mm2), sharpness threshold was very close to pressure threshold. As probe size(More)
Thresholds for the perception of coolness and heat pain were determined in sessions that randomly intermixed temperature increases and decreases. Four body sites were tested bilaterally: thenar eminence of the hand, plantar surface of the foot, dorsolateral forearm, and lateral calf. Coolness thresholds were lowest for the hand, intermediate for the(More)
Twenty-four healthy human subjects provided thresholds for their perception of pressure, sharpness, and pain. Mechanical forces were applied to the dorsal surface of the digits with flat-tipped probes of various sizes. Thresholds (expressed as force) increased with increasing probe size, as previously described. There was no evidence of a laterality(More)
Psychophysically, spatial summation can be demonstrated as a decrease in threshold accompanying an increased field of stimulation. The present study examined to what extent different mechanically evoked percepts (pressure, sharpness, and pain) show spatial summation. Various probes were used to apply prescribed forces to the dorsal surface of the digits of(More)
1. The responses of feline cutaneous nociceptors were examined in vivo by systematically manipulating the intensive and spatial dimensions of mechanical stimulation. A computer-controlled motor was used to apply prescribed forces (5-90 g) to a nociceptor's receptive field, with flat-tipped, cylindrical probes of various sizes (contact areas: 0.1-5.0 mm2).(More)
Thirty-two healthy human subjects provided thresholds for the perception of slight and moderate heat pain. Four body sites were tested bilaterally: thenar eminence of the hand, plantar surface of the foot, dorsolateral forearm, and lateral calf. Thresholds for the glabrous skin of the hand and foot were significantly greater than thresholds for the hairy(More)
The physiology of the superior colliculus (SC) implicates it in the visual control of eye movements. In the primate, acute inactivation of the superior colliculus delays the onset of a visually guided saccade, slows its velocity, and shortens its amplitude. Previous research leaves uncertain whether other oculomotor disorders which sometimes follow ablation(More)
Fourteen healthy subjects (4 males, 10 females) were asked to localize a thermal stimulus applied to the left distal forearm. Two temperature-controlled probes (1,2-cm2 area each) were strapped to the forearm, separated by 8 cm. The probes were positioned in one of three ways: (1) longitudinally within the C6 dermatome, (2) longitudinally within the C8(More)
Several aspects of tactile, thermal and pain perception were evaluated in an individual (R.S.) with a hemorrhagic lesion centered in her left lateral thalamus. Over a 4-year period, psychophysical evaluations were undertaken every 6-8 months, and five magnetic resonance (MR) studies were conducted. Early tests (1991-1992) revealed large contralateral(More)
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